CVE-2010-1633 in OpenSSL
Summary
by MITRE
RSA verification recovery in the EVP_PKEY_verify_recover function in OpenSSL 1.x before 1.0.0a, as used by pkeyutl and possibly other applications, returns uninitialized memory upon failure, which might allow context-dependent attackers to bypass intended key requirements or obtain sensitive information via unspecified vectors. NOTE: some of these details are obtained from third party information.
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Analysis
by VulDB Data Team • 09/14/2021
The vulnerability described in CVE-2010-1633 represents a critical security flaw in OpenSSL's cryptographic implementation that affects versions prior to 1.0.0a. This issue specifically impacts the EVP_PKEY_verify_recover function which is part of OpenSSL's public key infrastructure operations. The vulnerability manifests when the function attempts to verify cryptographic signatures and recover the original message, but fails to properly handle memory allocation during error conditions. The flaw allows the function to return uninitialized memory contents when signature verification fails, creating potential information disclosure risks that could be exploited by attackers with contextual knowledge.
The technical implementation of this vulnerability stems from improper memory handling within the EVP_PKEY_verify_recover function where the system does not adequately clear or initialize memory buffers before returning them to calling applications. This behavior creates a scenario where sensitive data that may have previously resided in memory locations could be inadvertently exposed through the function's return values. The vulnerability is particularly concerning because it affects the pkeyutl utility and potentially other applications that rely on OpenSSL's EVP_PKEY functions for cryptographic operations. According to CWE-248, this represents an exposure of uninitialized memory, which falls under the category of improper initialization of resources that can lead to information disclosure and potentially more serious security implications.
The operational impact of this vulnerability extends beyond simple information disclosure as it can enable attackers to bypass intended cryptographic security measures. When applications use the affected OpenSSL functions, they may unknowingly process uninitialized memory as valid cryptographic data, potentially allowing malicious actors to extract sensitive information from memory or manipulate cryptographic operations. This issue particularly affects systems that rely heavily on OpenSSL for secure communications, digital signatures, and certificate validation processes. The vulnerability aligns with ATT&CK technique T1552.001, which involves the exploitation of credential dumping and information disclosure through improper handling of cryptographic functions.
Mitigation strategies for this vulnerability require immediate patching of OpenSSL installations to version 1.0.0a or later where the memory handling has been corrected. Organizations should conduct comprehensive inventory assessments to identify all systems running vulnerable OpenSSL versions and prioritize remediation efforts accordingly. Additionally, security monitoring should be enhanced to detect potential exploitation attempts through unusual cryptographic operation patterns. The fix implemented in OpenSSL 1.0.0a addresses the core issue by ensuring that uninitialized memory is properly handled during verification failure scenarios, preventing the accidental exposure of sensitive data that could have been previously stored in the affected memory locations. System administrators should also review application configurations to ensure that cryptographic operations are properly validated and that error handling routines adequately protect against information leakage from memory operations.